This invention relates to an oil filter of the type that is normally used on internal combustion engines, such as automobile, bus, truck and boat engines although oil filters are also standard equipment for stationary engines. Oil used to lubricate an internal combustion engine entrains solid contaminants as the consequence of engine performance, that is, lubricating oil picks up carbon deposits that results from burning of fuel, debris resulting from engine wear, rust from metal engine components and so forth. Unless these solid materials are extracted from a circulating lubricant, the life expectancy of an engine can be decreased. Accordingly, virtually every internal combustion engine of any significant size, employs, as an important part thereof, an oil filter. Engine manufacturers prescribe periodic replacement of oil filters.
The most common type of oil filter in use today, particularly for vehicle engines, is a disposable filter in which the filter housing, having the filter element therein, is factory sealed. When the typical oil filter must be replaced it is necessary that the entire filter assembly, including the housing, mounting plates, bypass valve system, anti-drain back system and so forth that make up a filter be removed as a unit and discarded. Since frequent filter changes are recommended by engine manufacturers a huge number of oil filters are disposed of daily in the United States and all other industrialized countries of the world. Disposing of oil filters that include the entire metal housing, mounting plate, filter element, valve structures, etc., represent a serious source of contamination of the environment. The typical oil filter in use today can be disposed of only in a landfill, that is, the typical oil filter cannot be disposed of by burning to produce useable heat because of the substantial metal components and since the only combustible components are shielded within the metal housing.
In addition to the increased burden placed on the environment by metal housed disposable oil filters in use today, the currently popular replacement oil filters are more expensive than necessary.
An object of the present invention is to provide an improved oil filter in which the filter housing is intended for permanent, or at least long term use, on an internal combustion engine.
Another object is to provide an oil filter system in which the filter element consisting substantially entirely of easily combustible components so that it can be disposed of by burning rather than burial in a landfill. Accordingly, this invention achieves not only economy of filter replacement but a significant reduction in the burdens imposed on landfills or other trash disposable systems that are imposed by the huge number of metal housed oil filters that must be disposed of each day in the world.
Another objective is to reduce the amount of waste during an oil change by providing a filter system having a permanent valving arrangement.
In addition to providing more economical and environmentally acceptable oil filters, this invention provides waste reducing anti-drain back and bypass valve structures.